From ...
From: Erik Naggum
Subject: Re: Floating Point speed in Common Lisp
Date: 1998/03/16
Message-ID: <3099027379447143@naggum.no>#1/1
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References: <6e1v1c$7el@desire.lavielle.com> <4n1zw8j50i.fsf@rtp.ericsson.se> <87btvc8m8q.fsf@isttest.bogus> <4nwwe0gesm.fsf@rtp.ericsson.se> <87n2ev265j.fsf@isttest.bogus> <4nu393hj8t.fsf@rtp.ericsson.se> <87lnuf1yd6.fsf@isttest.bogus> <4npvjrh6g6.fsf@rtp.ericsson.se> <87iupj12zo.fsf@isttest.bogus> <35096D58.B149D0B5@computer.org> <3098801908586746@naggum.no>
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Newsgroups: comp.lang.lisp
* Matthew McDonald
| Do you have any examples to substantiate this claim?
not any good set of particular examples, but 15 years of experience with
C on lots of platforms and lots of compilers has alerted me to the fact
that C compilers and environments differ _very_ much in quality, more
than my experience with (native-compiled) Common Lisp implementations and
environments do. Common Lisp implementations are generally quite good,
but the same is not necessarily true for C compilers -- naive compilation
of C is often a viable option for small systems.
if you need a specific example, consider the bundled C compiler with
SunOS 4.X with the commercial compiler for Solaris 2.X. GCC 2.8.1 beats
the former by a factor of 1.7, but the Solaris 2.X commercial C compiler
appears to be slightly better than GCC.
I find it interesting that you jump up to require substantiation of the
claim that C implementations differ, but do not challenge that Common
Lisp implementations do. this is the general sentiment out there, as
sort of a cultural requirement on programmers.
C is not fast. C is primitive, which means it has a potential of being
fast if the programmer is a genius and the compiler is on his side. if
the programmer is an idiot, and the compiler expects smarter programmers,
you will get abysmal performance. e.g., a system currently written in C
but which I am replacing with one rewritten in Common Lisp shows a
promise of reducing system requirements by a factor of between 5 and 6,
after months of work to decipher the incredibly bad C code to figure out
what it actually does.
#:Erik
--
religious cult update in light of new scientific discoveries:
"when we cannot go to the comet, the comet must come to us."